RyanS

1990 3vze just did head gaskets and rebuilt the heads. When I first started it it ran like crap so I had to advance the distributor all the way for it to even idle still ran pretty weird. I pulled the distributor back out and re set it one tooth to the left which put the rotor just at/a hair before cyl. 1. It instantly started running perfect right in the middle mark of the adjustment.

I thought awesome and hooked up my timing light. It is way retarted according to my light like off the chart 1 inch towards the right of 0. If I advance it it starts to run like ˟˟˟˟ when it hits 0. What am I missing.

rebuilt heads
brand new distributor
timing belt checked and all mark's line up
new harmonic Balancer

I'm thinking maybe possibly my timing light is bad because it runs pretty good like that. Could it possibly be TPS? It runs really good, but I did notice when I jump te1 and e1 the idle doesnt really drop. any help?

scope103

My first guess is a slipped harmonic balancer (there is an annular rubber ring which can fail). But yours is new ....

I'd still check it; it's easy to do. Pull the #1 plug and feel for the piston coming to TDC with a wooden chopstick or plastic straw (a screwdriver risks gouging).

Does your timing light have one of those fancy dials to set the timing #?

RyanS

I've already confirmed the balancer is true and no my light is an old school craftsman non dial

Andy A

Just a thought but, did you jumper the diagnostic pins. Edit sorry looks like you have done that already.

cheers

Co_94_PU

iTrader: (-1)

If your balance mark is properly indicating TDC, and your timing light is showing retarded while a visual of the distributor is showing a slight advance.. You've probably got the wrong cam timing.

scope103

Hmm. How would that be? If the cam timing was off, how would that affect when the spark plugs fire (once he's repositioned the distributor on the now-rotated cam)?

Co_94_PU

iTrader: (-1)

cam drives the distributor on the 3vze, looks like it from here..

If it (timing belt) slipped the valves are closing early or late (advanced/retarded). If the distributor is placed while the crank indicates TDC, it fires the spark while valves aren't fully sealed. Reinserting the distributor a tooth in "the right" direction will have the spark occur at a more proper time with respect to the valve closure. The cam and valve timing will still be off, this could be in either direction. In this case the crankshaft is indicating valves are (maybe) closing late. Which should show up as a (large-ish) loss of power. This is the better of the two scenarios, if the valves close early and the ignition fires it's likely to trash the bearings or bend a rod..

I gotta run so hopefully that all came out correctly.
​*Edited some typos*

Co_94_PU

iTrader: (-1)

Please double check the TDC indicator, sparkplug out straw in hole should move up and down if the crank is rocked back and forth a few degrees) then try another timing light. Checking the cam timing isn't as trivial to-do on the 3vz as it is the R series if I'm not mistaken.

If the cam timing is retarded (or the valves were shimmed incorrect) it should show up the same as a burnt exhaust valve with the tail pipe test. (Slight suction, as the pistons move down before the valve closes).

COMTB

I just did my timing belt (finished it Friday 12/21), to me it sounds like something is not lined up correctly. My belt was cracking all over the place and before changing it I used a light and it was variable at about 2 degree delta but after a new cap/rotor I got it set at 12 degrees at idle.

Changing it, with everything at TDC and the two cam gears lined up (you have to twist the cam gear slightly driver and line the paint marks up)m I ve rified with a full cycle of the motor via breaker bar before putting the timing cover on and everything came back lined up correctly.

I checked my timing post install and it is now 8 degrees, so with the new belt i lost 4 degrees somewhere. I have pictures of the my old belt I can post if anyone is curious.

I also have the Toyota FSM with step by step instructions for the timing change if you have questions I can post pictures.

bensyota